The invention relates to an engine apparatus for a flying object, comprising a combustion chamber having a throat region and a nozzle region, said nozzle region having a nozzle wall, wherein the nozzle region expands from the throat region towards an exit end of the nozzle region relative to a combustion chamber axis.
The invention further relates to a flying object.
Furthermore, the invention relates to a test stand or a launching ramp for a flying object.
Furthermore, the invention relates to a method for reducing a side load in an engine apparatus, particularly in a startup phase and/or in a shutdown phase.
U.S. Pat. No. 4,480,437 discloses an unfoldable device for extending the nozzle of a rocket motor, consisting of a frustoconical skirt formed by a stack of tube rings or coils that are welded together. The tube rings or coils have a cross-section that is flattened in the direction of the stack. Furthermore, a pyrotechnic device is provided which is received in the tube and is capable of generating sufficient pressure in order to increase the dimensions of the tube in the direction of the stack after ignition.
U.S. Pat. No. 3,249,306 discloses an automatically adjustable nozzle for a rocket, comprising a fixed-diameter part that surrounds an outlet of a combustion chamber of a rocket motor. Furthermore, an elongated tubular skirt is provided that is secured at its forward end to said fixed-diameter part and extends rearwardly therefrom. The wall of said skirt has a plurality of longitudinally extending corrugations.
U.S. Pat. No. 2,967,393 discloses a rocket.
JP 07139431 A discloses a nozzle in which an inner cylinder is fixed to an inner circumferential surface of the nozzle by means of a separation bolt.
During the startup operation and also during the shutdown operation of an engine apparatus in a flying object and particularly a rocket, separation of flow takes place in the supersonic part of the nozzle region. Said flow separation is asymmetrically distributed around the circumference of the nozzle region and fluctuates. The asymmetric distribution leads to high side loads. The side loads occurring during the startup operation and the shutdown operation of an engine apparatus may reach magnitudes that are far beyond the side loads of an engine apparatus operating at nominal combustion chamber pressure.